One methods used in helping to manage intestinal lymphangiectasia is to follow a specialized diet involving what is called medium chain triglycerides.

Here is some helpful information on MCT's, what they are and what they do.

Medium Chain Triglycerides

What do they do?

Medium-chain triglycerides (MCT) are a class of fatty acids. Their chemical composition is of a shorter length than the long-chain fatty acids present in most other fats and oils, which accounts for their name. They are also different from other fats in that they have a slightly lower calorie content1 and they are more rapidly absorbed and burned as energy, resembling carbohydrate more than fat.2

MCT have been shown to increase calorie burning compared with other fats.3 4 However, researchers estimate that half of the calories in the diet would have to be eaten as MCT for significant weight loss to occur.5 Obese women on a calorie-restricted diet using MCT for 24% of total calories, experienced no greater weight loss after three months, than when regular fat was used.6 Whether MCT would help people lose weight on a normal diet has not been adequately studied.

Since MCT is more rapidly used for energy than other fats, some athletes have been interested in its use, especially during prolonged endurance exercise.7 However, no effect on carbohydrate sparing or endurance exercise performance has been shown, with moderate amounts of MCT (30–45 grams).8 9 Trials using very large amounts (about 85 grams) have produced conflicting results. One study found increased performance when MCT was added to a 10% carbohydrate solution,10 and another study actually reported decreased performance, probably due to gastrointestinal distress, in athletes using MCT.11

Because some short-term studies have shown that MCT lowers blood glucose levels, a group of researchers investigated the use of MCT to treat people with type 2 (adult onset or non-insulin-dependent) diabetes mellitus.12 In nonhospitalized people with diabetes who consumed MCT for an average of 17.5% of their total calorie intake for 30 days, MCT did not improve diabetic control by most measures.13

Where are they found?

Medium chain triglycerides are found in coconut oil, palm kernel oil, and butter. MCT are also available as a supplement.

Who is likely to be deficient?

Most people consume adequate amounts of fat in their diets and many people consume excessive amounts, so extra fat intake as medium chain triglycerides is unnecessary.

How much is usually taken?

The best amount of medium chain triglycerides to take is currently unknown. Athletes are not likely to benefit from less than 50 grams during exercise. Larger amounts may possibly help some, but may also impair performance if not combined with carbohydrate.

Are there any side effects or interactions?

Consuming medium chain triglycerides on an empty stomach can lead to gastrointestinal upset. Anyone with cirrhosis or other liver problems should check with a doctor before using MCT. Two reports suggest that MCT may raise serum cholesterol and/or triglycerides.14 15 MCT is actually the preferred fatty acid source for cirrhotic patients, but only when used intermittently.16

At the time of writing, there were no well-known drug interactions with medium chain triglycerides.

Medium-chain triglycerides (MCTs) are a special class of fatty acids. Normal fats and oils contain long-chain fatty acids (LCTs). Compared to these fatty acids, MCTs are much shorter in length. Therefore, they resemble carbohydrates more than fat. As a result, they are more easily absorbed, digested, and utilized as energy than LCTs.

Medium-chain triglycerides are found naturally in milk fat, palm oil, and coconut oil. Commercial MCT oil, available as liquid and capsules, is obtained through lipid fractionation, the process in which MCTs are separated from other components of coconut oil. Medium-chain triglycerides were originally formulated in the 1950s as an alternative food source for patients who are too ill to properly digest normal fats and oils.

The long chains of LCTs require a lot of bile acids and many digestive steps to be broken down into smaller units that can be absorbed into the bloodstream. Once in the bloodstream, they are absorbed by fat cells and stored as body fat. In contrast, the medium-chain triglycerides are more water-soluble and are able to enter the bloodstream quicker because of their shorter lengths. Once in the bloodstream, they are transported directly into the liver. Thus, MCTs are an immediately available source of energy and only a tiny percent is converted into body fat.

Medium-chain triglycerides were first used in the mid-1900s to reduce seizures with the help of the ketogenic diet. In the 1980s, MCTs became popular in sports as a substitute for normal dietary fats or oils. They quickly became a favorite energy source for many athletes, such as marathon runners, who participate in endurance sports. These athletes require a quick source of energy, which is readily supplied by carbohydrates. However, diets high in carbohydrates may cause rapid increase in insulin production, resulting in substantial weight gain, diabetes, and other health problems. Dietary fats or oils are not a readily available source of energy. In addition, they are believed to make the body fatter. MCT is also a form of fat; therefore, it is high in calories. Yet, unlike normal fats and oils, MCTs do not cause weight gain because they stimulate thermogenesis (the process in which the body generates energy, or heat, by increasing its normal metabolic, fat-burning rate). A thermogenic diet, which is high in medium-chain triglycerides, has been proposed as a type of weight loss regime.

General use

Endurance sport nutrition

Medium-chain triglycerides are often used by athletes to increase their endurance during sports or exercise regimes. MCTs are an immediate source of energy, and as such, the body can use them as an alternative energy source for muscle during endurance exercise. However, if consumed in moderate amounts (30 to 45 grams), MCTs are not very effective in either decreasing carbohydrate needs or in enhancing exercise endurance. Increased consumption may help.

One study evaluated six athletes at different points during a 25-mile cycling trial.

They were given either a medium-chain triglyceride beverage, a carbohydrate drink, or a combined MCT-carbo-hydrate mixture. The fastest speed was achieved when the athletes used the MCT-carbohydrate blend. The worst performance was associated with sport drinks containing MCT alone (without carbohydrate). Therefore, to gain significant increases in endurance, it is generally recommended that an athlete consume at least 50 grams of MCTs per day in combination with some carbohydrates. However, dosages exceeding 30 grams often cause gastrointestinal upset, which can diminish an athlete's performance.

MCT products available in the market may have high water content or contain unwanted ingredients. Therefore, athletes should buy MCT-only products, and mix a small amount into carbohydrate soft drinks. Alternatively, they can purchase premixed MCT sport drinks, such as a brand known as SUCCEED.

Thermogenic diet

MCTs are popular among body builders because they help reduce carbohydrate intake, while allowing them ready access to energy whenever they need it. MCTs also have muscle-sparing effects. As a result, they can build muscles while reducing fats. However, this does not mean that these athletes will become healthier, because an improvement in body physique does not always correlate with higher fitness levels.

Pre-competition diet

Compared to carbohydrates, medium-chain triglycerides are a better and more efficient source of quick energy. They help conserve lean body mass because they prevent muscle proteins from being used as energy. Therefore, some athletes load up on medium-chain triglycerides the night before a competition. However, MCT intake should be raised gradually to allow the body to adapt to increasing MCT consumption.

If MCT consumption abruptly increases, incomplete MCT metabolism may occur, producing lactic acid in the body and a rapid rise of ketones in the blood, which can make the person ill.

Weight-loss diet

Studies have shown that MCT may increase metabolism, which is the rate that the body burns fat. It is believed that sustained increases in metabolic rate cause the body to burn more fat, resulting in weight loss. However, for any kind of meaningful weight loss, a person would have to consume more than 50% of total daily caloric intake in the form of medium-chain triglycerides.

Treatment of seizures

A ketogenic diet, or diet containing mostly medium-chain triglycerides, offers hope for those who have seizures that cannot be controlled by currently available drugs. Excessive consumption of MCTs produces ketones in the body; therefore, this type of diet is called a ketogenic diet. It has proven effective for some epileptic patients.

Nutritional supplements

MCTs are the preferred forms of fat for many patients with fat malabsorption problems.

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Many diseases cause poor fat absorption. For instance, patients with pancreatic insufficiency do not have enough pancreatic enzymes to break down LCTs. In children with cystic fibrosis, thick mucus blocks the enzymes that assist in digestion. Another fat absorption condition is short-bowel syndrome, in which parts of the bowel have been removed due to disease. Stressed or critically ill patients also have a decreased ability to digest LCTs. Unlike LCTs, medium-chain triglycerides are easily absorbed by patients with malabsorption conditions. These patients benefit most from oral preparations that contain MCTs as the primary source of fat (up to 85% of fat caloric intake). Several scientific studies have shown MCT to be effective in treating fat malabsorbtion, chronic diarrhea, and weight loss in patients with Acquired Immune Deficiency Syndrome (AIDS).

Many MCT products can be found in local health food stores or ordered through pharmacies. Before purchasing these products, patients should consult their doctors or registered dietitians for advice concerning appropriate dosage and use. MCT oil is not used for cooking. However, it can be used for tube feeding in critically ill patients. Healthy people may take it orally, by itself or mixed with water, juice, ice cream, or pudding.

Preparations

Available medium-chain triglyceride products include:

·MCT oil
·sports drinks
·energy bars
·meal replacement beverages

Precautions

·People with hepatic encephalopathy, brain and nervous system damage
that occurs as a complication of liver disorders, should not take MCT.

·Long-term high-level MCT consumption is associated with increased risk of heart disease and other conditions. Even moderate consumption of medium-chain triglycerides can increase cholesterol and triglyceride levels. Therefore, no more than 10% of a person's diet should come from MCTs.

·Diabetic athletes and those with liver disease should not use MCT products.

·MCT oil should not completely replace all dietary fats, as this would result in a deficiency of other fatty acids- essential fatty acids- that the human body needs from food sources. To avoid essential fatty acid deficiencies, a person should also include omega-3 and omega-6 fatty acids in their diets. Good sources of omega-3 include fish, fish oils, or flaxseed oil. Omega-6 fatty acids are often found in vegetable oils and evening primrose oil. The omega-3 fats have several additional health benefits, such as alleviating inflammation and protecting the body against heart disease.

·A person should not take medium-chain triglyceride products on an empty stomach, as this may cause gastric upset.

·MCT oil is not for cooking. It is usually consumed in its uncooked form as sport bars, or mixed with a carbohydrate drink, protein shake, or other products.

·MCT oil leaches into plastic bags and containers. Therefore, non-plastic containers should be used for MCT oil storage.

Side effects

There are a few adverse effects associated with MCT use. Eating foods containing medium-chain triglycerides on an empty stomach often causes gastrointestinal upset. Regular consumption of MCTs may increase cholesterol and triglyceride blood levels.

Interactions

There have been no reported interactions between MCTs and other drugs.
Resources

Medium-chain triglycerides, commonly abbreviated MCT or MCTs, are medium-chain fatty acid esters of glycerol. Medium-chain fatty acids are fatty acids containing from six to 12 carbon atoms. These fatty acids are constituents of coconut and palm kernel oils and are also found in camphor tree drupes. Coconut and palm kernel oils are also called lauric oils because of their high content of the 12 carbon fatty acid, lauric or dodecanoic acid.

Medium-chain triglycerides used for nutritional and other commercial purposes are derived from lauric oils. In the process of producing MCTs, lauric oils are hydrolyzed to medium-chain fatty acids and glycerol. The glycerol is drawn off from the resultant mixture, and the medium-chain fatty acids are fractionally distilled. The medium-chain fatty acid fraction used commercially is mainly comprised of the eight carbon caprylic or octanoic acid and the 10 carbon capric or decanoic acid. There are much smaller amounts of the six carbon caproic or hexanoic acid and the 12 carbon lauric acid in the commercial products. The caprylic- and capric-rich mixture is finally re-esterified to glycerol to produce medium-chain triglycerides that are mainly glyceral esters of caproic (C6) caprylic (C8), capric (C10) and lauric acid (C12) in a ratio of approximately 2:55:42:1.

MCT is also known as fractionated coconut oil. In a process called interesterification, long-chain fatty acids, such as oleic and linoleic acid, are introduced into the final product. MCT derivatives produced by the interesterification process are referred to as structural lipids or structural triglycerides. Unlike most natural oils of animal or vegetable origin, MCT is stable and resistant to oxidation owing mainly to the saturation of the medium-chain fatty acids.

ACTIONS AND PHARMACOLOGY

ACTIONS

MCT's major action is as an energy-yielding substrate, particularly beneficial for those with malabsorption syndromes. MCT is also ketogenic.

MECHANISM OF ACTION

The physiology and biochemistry of medium-chain triglycerides are very different from those of long-chain triglycerides. MCT is rapidly absorbed from the small intestine, intact or following hydrolysis, into the portal circulation. From there, it is transported to the liver. Long-chain triglycerides are first hydrolyzed in the small intestine to long-chain fatty acids. They are in turn re-esterified in the mucosal cells of the small intestine to long-chain triglyerides, which are then carried by chylomicrons and transported via the lymphatic system to the systemic circulation. The systemic circulation in turn distributes the long-chain triglycerides to various tissues of the body, including adipose tissue and the liver.

Since MCT, in contrast with long-chain fatty acids, does not require pancreatic enzymes or bile salts for digestion and absorption, MCT is better handled in those with malabsorption syndromes than are the long-chain fatty acids. These syndromes include pancreatic disorders, hepatic disorders, gastrointestinal disorders and disorders of the lymph system.

Medium-chain fatty acids are taken up by hepatocytes and converted to medium-chain fatty acyl CoA which enters mitochondria without requiring the aid of carnitine. On the other hand, long-chain fatty acids, which are also converted to their coenzyme A esters in cells, including hepatocytes, require that they be converted from coenzyme A esters to carnitine esters in order to be transported across the mitochondrial membrane. Within the hepatocyte mitochondria, medium-chain fatty acyl CoA is converted to acetoacetate and beta-hydroxybutyrate and subsequently to carbon dioxide, water and energy. The oxidation of MCT produces 8.3 kilocalories of energy per gram ingested.

MCTs are therefore easier to metabolize, which could be advantageous to those who are critically ill and those with carnitine deficiencies.
MCT is ketogenic. The metabolism of MCT in hepatocytes produces two so-called ketone bodies, acetoacetate and beta-hydroxybutyrate. These ketone bodies are carried by the bloodstream to other tissues of the body, where they are used for energy production, as well as for other biochemical processes. It is believed that ketosis may raise the seizure threshold and reduce seizure severity. This is still hypothetical but is the rationale for the use of ketogenic diets in the treatment of seizure disorders.

PHARMACOKINETICS

MCT is rapidly absorbed from the small intestine, intact or hydrolyzed, after ingestion and is transported to the liver via the portal circulation. Medium-chain fatty acids are transported into hepatocytes and converted to medium-chain fatty acyl CoA esters. Medium-chain fatty acyl CoAs (mainly of caprylic and capric acids) are transported into mitochondria, where they are metabolized to acetoacetate and beta- hydroxybutyrate. The first mitochondrial enzyme in this process is medium-chain acyl CoA dehydrogenase. Acetoacetate and beta-hydroxybutyrate may be further metabolized in the liver to carbon dioxide, water and energy, and may enter some other metabolic pathways in the liver or be transported by the systemic circulation to other tissues, where they undergo metabolism mainly to CO2, H2O and energy. Very little ingested MCT is deposited in the body as fat.

INDICATIONS AND USAGE

Though MCT's are being promoted in the supplement marketplace for weight loss and to increase athletic performance, numerous studies have shown that MCT's are ineffective for achieving these goals. On the other hand, MCT does appear to be helpful for nutritional support in a number of conditions, including enteral and total parenteral nutrition in some infants and surgical patients, as well as in some of those who are critically ill with immunosuppression, pulmonary disease, liver disease, neurologic injury and various malabsorption syndromes. MCT may also be useful in some with epilepsy and other disorders characterized by seizures. There is preliminary evidence that MCT may be helpful in some cancers and may have some positive effects on immunity.

RESEARCH SUMMARY

A large number of studies have sought to determine whether MCT can promote long-chain fatty acid oxidation, inhibit the rate of muscle glycogen depletion, and enhance exercise and athletic performance. Many of these studies have tested subjects, some of them elite athletes, on bicycle ergometers. Some of these trials have been randomized, double-blind, placebo-controlled. Almost all have found no effect of MCT on rates of long-chain fatty acid oxidation, muscle glycogen utilization or performance. "At present," one research group concluded, "there is insufficient scientific evidence to recommend that athletes either ingest fat, in the form of MCTs, during exercise, or "fat adapt' in the weeks prior to a major endurance event to improve athletic performance."

It should be noted that some have reported that exercise performance is actually impaired in some taking high doses of MCT. This diminished performance was associated with increased gastrointestinal complaints, primarily intestinal cramping.

Research on weight loss associated with MCT intake is not as abundant but presents a mixed and mostly negative conclusion. MCT diets have been compared with LCT (long-chain triglyceride) diets and show no superiority. There are no convincing data that diets high in MCT are effective for weight loss.

MCT shows considerable promise, on the other hand, for the nutritional support of some premature infants, surgical patients and the critically ill, particularly those needing total parenteral nutrition (TPN). Lipid emulsions containing significant quantities of MCT as part of TPN have demonstrated significant benefits in some with pulmonary diseases, AIDS, liver disease, neurologic injury and several other illnesses.

AIDS patients, for example, who were suffering from fat malabsorption and chronic diarrhea with weight loss, were significantly benefited by a 12-week regimen of MCT. There was a significant decrease in stool number, stool fat and stool weight compared with baseline, regardless of the etiology of the diarrhea.

Surgical patients have shown more improvement in some studies, using MCT, compared with LCT. The same is true in some patients with some forms of liver disease. MCT is more readily utilized than LCT and is not deposited in the liver. MCT combined with LCT was found to be superior to LCT alone in septic patients with ARDS. Nutritional support with MCT has also helped prevent gestational hyperlipidemic pancreatitis, with resulting successful childbirth.

MCT's usefulness in drug-resistant epilepsy was demonstrated in a trial with 50 children, eight of whom achieved complete control of seizures (four without further use of anticonvulsant drugs). In another trial, five of 17 MCT-treated subjects with previously intractable drug-resistant seizures achieved complete control of seizures with diminished or discontinued use of drugs. Five others had some improvement. Other types of intractable seizures have also yielded to MCT supplementation. Seven girls with Rett syndrome who suffered from drug-resistant seizures were given MCT therapy; five showed clinical benefit.

There is very preliminary evidence that MCT may have some positive effects on immunity and may exert some anti-cancer effects. Compared with LCT, MCT enhanced macrophage response in an animal model and suppressed Malassezia infection in vitro. This is significant, in particular, since lipophilic Malassezia species frequently grow on standard lipid infusions and can induce catheter-associated sepsis in newborns and immunocompromised patients receiving parenteral lipids.

In an animal model of cachexia-inducing colon adenocarcinoma, an MCT regimen reduced weight loss and was associated with a marked reduction in tumor size. LCT, on the other hand, did not have these effects. In vitro studies have indicated that MCT is significantly cytotoxic against some human tumor cells. More research is underway.

CONTRAINDICATIONS, PRECAUTIONS, ADVERSE REACTIONSCONTRAINDICATIONS

MCT is contraindicated in those with hepatic encephal- opathy.

PRECAUTIONS

Great caution should be exercised in the use of MCT in those with diabetes, acidosis, ketosis, cirrhosis and the inborn error of metabolism, medium-chain acyl CoA dehydrogenase deficiency. Those with cirrhosis may accumulate free fatty acids and glycerol if given MCT.

MCT may facilitate the absorption of magnesium, calcium, fat-soluble vitamins and other lipophilic nutrients (carotenoids, flavonoids) and long-chain fatty acids in foods.

HERBS

Theoretically, MCT may facilitate the absorption of lipophilic substances in herbs.

OVERDOSAGE

There are no reports of overdosage with MCT.

DOSAGE AND ADMINISTRATION

Medium-chain triglycerides are available in several medical food products, many for use in a hospital setting. Doses of these medical food products are as prescribed by a physician.

MCT (100 percent) is available as a nutritional supplement. Those with malabsorption syndromes typically use one tablespoon up to three times a day with food or as directed by a physician. One tablespoon is equivalent to approximately 15 grams of MCT.

Those who use MCT as a supplement for any other reason typically use one tablespoon once to three times daily taken with food.

Doses greater than 80 grams (over five tablespoons) taken at one time may cause intense intestinal cramping.